/*
 * R : A Computer Language for Statistical Data Analysis
 * Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka
 * Copyright (C) 1997--2008  The R Development Core Team
 * Copyright (C) 2003, 2004  The R Foundation
 * Copyright (C) 2010 bedatadriven
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.renjin.stats.internals.distributions;

import org.renjin.eval.Session;

public class Weibull {

  public static double rweibull(Session context, double shape, double scale) {
    if (Double.isInfinite(shape) || Double.isInfinite(scale) || shape <= 0. || scale <= 0.) {
      if (scale == 0.) {
        return 0.;
      } else {
        return (Double.NaN);
      }
    }
    return scale * Math.pow(-Math.log(context.rng.unif_rand()), 1.0 / shape);
  }
}
